It has hitherto been known that particular kinds of uracil derivatives have herbicidal activity, and there are commercially available herbicides containing such uracil derivatives, for example, under the common name "BROMACIL". U.S. Pat. Nos. 3,920,653 and 4,859,229 disclose some amino uracil and phenyl uracil derivatives, respectively, both of which can be used as an active ingredient of herbicides.